Radeon HD 4770 vs Radeon HD 7850

Intro

Compare those specifications to the Radeon HD 7850, which comes with a core clock frequency of 860 MHz and a GDDR5 memory speed of 1200 MHz. It also features a 256-bit memory bus, and uses a 28 nm design. It features 1024 SPUs, 64 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 7850		130 Watts
	Difference: 50 Watts (63%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7850 will be 200% quicker than the Radeon HD 4770 overall, due to its greater data rate. (explain)

Radeon HD 7850		153600 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 102400 (200%)

Texel Rate

The Radeon HD 7850 should be much (approximately 129%) better at anisotropic filtering than the Radeon HD 4770. (explain)

Radeon HD 7850		55040 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 31040 (129%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7850 is a better choice, and very much so. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 15520 (129%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of information (counted in megabytes per second) that can be transported over the external memory interface within a second. It's calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.